National Estuarine Research Reserve System

Centralized Data Management Office

Quality Assurance and Quality Control (QAQC)

All NERR SWMP data incur primary data QAQC at the CDMO within one week of data retrieval as the provisional data are ingested into the CDMO database. The data are then emailed back to the Reserve where Reserve staff use tools provided by the CDMO, Microsoft Excel macros, to perform secondary QAQC on the data. Data that have been through secondary QAQC are submitted back to the CDMO quarterly and again annually; these data are posted as provisional plus. After annual submission to the CDMO is complete, the data undergo final tertiary QAQC by the CDMO. The data and its accompanying metadata documentation are checked for completeness before dissemination as authenticated historical data via the CDMO Online Data Information Server (

SWMP Status

SWMP stations have either primary or secondary status. Primary SWMP stations are the core monitoring stations required by the NERRS and undergo all levels of QAQC. Secondary SWMP stations are additional, optional stations which must follow all SWMP data collection, submission and QAQC protocols. However, with the exception of nutrient monitoring stations, secondary SWMP data do not go through tertiary review by the CDMO.

QAQC Status

The values in the historical and provisional plus columns of the exported data indicate what stage of QAQC the data are in. The QAQC status is also shown on the charts when mousing over a value. There are three QAQC stages reported:

Provisional data have been through an automated flagging process (primary QAQC) only and have not been checked by the Reserve. The automated flagging process currently flags data that are out of sensor range or missing. Provisional data are indicated with a value of 0 in the provisional plus column of exported data files, and with a QAQC: P in a chart mouse-over.

Provisional plus data have been reviewed by the Reserve staff (secondary QAQC) using Excel macros to further QAQC the data. Provisional plus data are indicated with a value of 1 in the provisional plus column of exported data files, and with a QAQC: PP in a chart mouse-over.

Authenticated data have been through final tertiary review at the CDMO and are posted as the final authoritative data. Authenticated data are indicated with a value of 1 in the historical column of exported data files, and with a QAQC: A in a chart mouse-over. A value of 0 in the historical column indicates that the data have not been through final QAQC by the CDMO, and could be either provisional or provisional plus data.

QC Flags

Each parameter in the exported data file contains a flag column. The flag column, F_param, contains a quality control (QC) flag and may contain additional QC codes. In a chart mouse-over, the QAQC flag and any codes are displayed behind the F_param: designation. Refer to the list below for the available QC flags and their descriptions.

QC Codes by Dataset

To learn more about the water quality, meteorological and nutrient parameters and units collected for the System-wide Monitoring Program, visit the parameter explanation page at

Please contact if you have any questions regarding the data or the QAQC process used.